inductance
Inductance measures how strongly a coil opposes a change in current, that is, how big the current flywheel is. A larger inductance stores more magnetic energy for the same current and produces a bigger opposing voltage when the current tries to change.
Precisely, inductance L relates voltage to the rate of current change, V = L times dI/dt, and is measured in henries (H). One henry is one volt per (amp per second). Real parts are millihenries (10^-3 H) or microhenries (10^-6 H). More turns, a magnetic core, and tighter winding all raise L. The energy stored is (1/2) times L times I^2, so a 10 mH inductor carrying 2 A holds (1/2)(0.01)(4) = 0.02 joules.
Inductance sets the energy a switching converter shuttles each cycle and, together with capacitance, sets resonant frequencies. Caveat: every wire and PCB trace has a little stray (parasitic) inductance, usually unwanted. At high speed even a short lead's inductance matters, which is why decoupling capacitors must sit physically close to the chip they feed.
A buck converter's 22 uH inductor stores energy each switching cycle; with 1 A flowing it holds (1/2)(0.000022)(1) = 11 microjoules, released to the output between pulses.
Inductance sets stored energy per cycle.
Inductance and capacitance are duals, not opposites in value. Swap the roles of current and voltage and one defining equation maps onto the other.